In U.S. Pat. No. 2,840,459, there is disclosed a process and apparatus for the continuous extraction of oils and/or soluble materials comprised of a large vessel forming a vapor-tight enclosure in which there is disposed a rotor including a plurality of cells formed by radially disposed inner walls extending toward and mounted to peripherally-disposed end walls. The bottom of each cell is provided with a hinged-door assembly including associated equipment for opening and closing each cell. Drainage compartments generally underlie the cells for collecting miscella, i.e. a solution of oil and solvent.
Such apparatus has found wide acceptance, with the design unit quantity of material capable of being treated per hour being a function of the diameter of the rotor. The rotor is supported by thrust bearings mounted on a housing. The size of such bearings incrementally increase with increasing diameter of the rotor with structural housing requirement in terms of weight also incrementally increasing with increasing diameter of the rotor, consequentially limiting as a practical matter the maximum diameter of a rotor and thus maximum design capacity thereof for the designed material being treated.